Synthèse de phosphinites dérivés de sucres: Applications en cyclodimérisation du penta 2,4-diénoate de méthyle, en hydrogénation et en hydrosilylation de la pentolactone
Sugar-derived phosphinites, when used as ligands in the catalytic hydrogenation of α-ketopentolactone, lead to the corresponding alcohol with a better enantiomeric excess (20%) than in hydrosilylation (10%). In the cyclodimerisation of penta-2,4-dienoic acid methyl ester they lead to the meso cycloocta-3,7-diene-1,2-doic dimethyl ester.
Organometallic compounds in organic synthesis. Part 13. Stereoselectivity of complexation of cyclohexadiene esters
作者:B. M. Ratnayake Bandara、Arthur J. Birch、Warwick D. Raverty
DOI:10.1039/p19820001755
日期:——
Complexation of cyclohexadienes with Fe(CO)3 as the entering group are subject to classical steric hindrance by alkyl groups, but CO2R and related groups introduce a competing factor because they favour sterically the entering group, probably through an intermediate complex. Increase of π-electron availability in the initial 1,4-diene by the attachment of OMe reduces this influence, probably because